Process for improving the magnetic qualities of a magnetic body.



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Specification otf Letters Patent. No Drawing. Application-'fileflHayoh'm, I907, SerialiNo. 363,655. 'Renewe The invention is a process 'for improving certain magnetic qualities of a magnetic body, and more especially of alloys ofiron and silicon, or iron-silicon-and aluminium or iron-silicon and manganese, in order to increase the magnetic permeability and electric resistance and lower the hysteresis action of the said body; and thus to adapt it for use in ballast-coils, transformer-plates and like electrical apparatus, where the reetic and electric losses to the lowest possibe degree is of great importance.

In U. S. Patent No. 745,829 granted to me December 1, 1903, I have set forth a moose which consists in heating the magnetic body to between about 900 and 1100 centigrade, allowing it to cool, preferably quickly then reheatin it to between about 750 a 850 centi ra e and thereupon allowing it to cool slow y. By my present invention, instead of cooling relatively rapidly after the first or high heating, I cool the material slowly, and, instead of cooling. slowly after the second or low heating, I cool the material. rap- Or, in other words, I first heat the magnetic body, specifically including in this term the particular alloys hereinbefore mentioned, to a temperature below its melting point, say between about 900 and 1000 centigrade, then cool it slowly, then reheat it to a lower temperature say between 700 and 800 centigrade and then cool it rapidly. By this process, I attain the desirable results hereinbefore set forth.

Cooling rapidly, as herein referred to, means cooling at such a rate as that the changes effected by raising the material to the definite temperature stated are retained substantially unaltered. Cooling slowly as herein referred to, means cooling at sue a rate as to permit the slow rearrangement'ot the molecules with reference to one another, so that the condition of strain or hardness is removed and the material becomes soft, often a companifil by a more uniform distributi -n mass.

of the elements throughout the I claim:

1. The process of PatentedDec. 30, F1913. d J'unc'2, 1913. Serial 310,771,3IL0.

ments, which consists in, first, heating'sa'id body .to a temperature below its melting point, cooling slowly, i to a lower temperature, and then cooling said alloy rapidly.

2. The process of netic and then heating said body reducing the total magelectric loss in an alloycontaining iron and silicon, which consists in first heating said alloy to a temperature ranging from about 900 C. to about 1000? 0., ing said alloy slowly, al 0y en coolthen reheating said to a temperature ranging from 7 00 C.

to about 800 C. and

to cool rapidly.

then causing said alloy 3. The herein'described process of reducing the total magnetic and electric loss in a magnetic body composed of iron allo ed with other elements which consists in rst heating said body to a-comparatively high temperature, below cooling the body slowly,

body to-a lower temperature" than its melting oint, then then re eating the before,

and then cooling said body rapidly.

4. The h erein described process of reducing the total magnetic and electric loss in a magnetic body composed of iron alloyed with other elements, heating said body to a high temperature below its melting point, then cooling said body slowly, then reheating 'said body to a temperature lower than about 100 C. lower? than the first temperature, and then cooling said body rapidly.

5. The process of reducing the total magmotif: and electric loss in a magnetic be composed of iron alloyed with-other elements which consists in first heating said body to a comparatively high temperature not substantially above cooling said b0 about -1000 (1, then y, then reheating said body to a high temperature but not substantially above about 800 C. and then cooling said hich consists in first composed of iron alloyed with other at: 5 pp body much more rapidly than the first cooling.

6. The process of reducing the total magnetic and electric loss in a magnetic be composed of iron alloyed with other elements which consists in first heating said body to comparatively a high temperature of about 900 C. to

about 1000" C. then cooling said body slowly as to permit the of the molecules so that slow rearrangement the condition of strain orhardness is reof about 700 C. to about 800 POlIlt, then cooling slowly,

moved and the material becomes soft, then reheating said body to a lower temperature C. and then cooling said body rapidly to retain substantially unaltered the changes eflected by raising the material to said temperature.

7. The herein described process of producing a magnetic material of high perrnem bility and low hysteresis action which con sists in alloyin iron with silicon and with another materia hi h temperature but below its melting then heating said body to a high temperatute but lower than the preceding and then cooling the same rapidly.

8. The herein described process of prothen heating said body to a ducing a magnetic material of high permeability and low hysteresis action which consists in alloying another material such as aluminium and phosphorus, then heating said alloy to a iron with silicon and with temperature of from about 900 C. to about 1000- (1., then cooling said alloy slowly,

then reheating said alloy to a temperature of from about 700C. to about 800 C. and then cooling said alloy rapidly.

In Witness whereof, I have signed my name hereto in the presence of two witnesses.

WILLIAM Cnoss, J OHN WM. CRAWLEY, 

